rebelpeon.com

CloudFlare

I was using CloudFlare for awhile, but realized it was causing a few issues. In practice it sounds like a great idea, essentially the same as any CDN, but free. However, when editing posts on other websites, WordPress was never able to adjust the ajax to format the text in the visual viewer. It wasn’t really that it didn’t render it, it was more that it would take until a timeout is hit to render anything in the body field.

Simply not acceptable. As soon as I deactivated CloudFlare, it worked great. Needless to say, it’s not something I really need, so I just removed it.

Migration to WordPress Network Part 2

I had two outstanding items to figure out before migrating my last site. Today I was able to knock off one.

My Director installation used to be a directory under my website. Unfortunately, with migrating to a wordpress network, that wouldn’t work. This is because everything is done via DNS redirection and so a directory doesn’t physically sit where you think it does. I can only think of the nightmares it could cause.

Instead, I moved it to a sub domain. This seemed to fix all the issues, and it is actually pretty nice there. I just had to update a few links on various pages, make a few php.ini updates, and all was well.

Now it’s on to the massive site. I think I have to import only a few records at a time. Turns out, with all the media attached to each post, it kept timing out.

Update: Well, that was a fun experiment. Since I can’t seem to upload any of my previous entries (Dreamhost kills the script), I’ve decided things are working ok with two WordPress installs, and that’s how it will stay. The other site is huge anyways, so it makes sense…

Net.TCP, IIS7, and Classic AppPools

With the application that I’m helping “make fast” one of the optimizations identified by an architect was to use net.pipe or net.tcp on the application tier. This was because the services on that tier call into each other, and waste a lot of time doing all the encapsulation that comes with wsHttpBinding.

We had tried to first use net.pipe because it is incredibly fast and it is all local. However, because of how they do security here, it didn’t work. Next up, net.tcp.

Overall, it wasn’t that difficult to setup the services with dual bindings (wsHttpBinding for calls from other servers and net.tcp for calls originating from the same server). Granted, there were a lot of changes, and since all the configs are manually done here, was very error-prone. I will be glad not to do any detailed configurations for a while.

Anyways, we did our testing of the build that incorporated it through 3 different environments, and over the weekend it went into Production. Of course, that is when the issues started.

Bright and early Monday morning, users were presented with a nice 500 error after they logged into the application. On the App tier servers we were getting the following error in the Application event log with every request to the services:

Log Name:      Application
Source:        ASP.NET 4.0.30319.0
Event ID:      1088
Task Category: None
Level:         Error
Keywords:      Classic
User:          N/A
Description:
Failed to execute request because the App-Domain could not be created. Error: 0x8000ffff Catastrophic failure

Well, since it mentioned the App Domain, we ran an IISReset and all was well. I didn’t think too much into it at the time and only did some cursory searching as it was the first time we saw it. However, today it happened again.

Our app is consistently used between 7AM and about 7PM, but during the night it isn’t used at all. This is when the appPool is scheduled to be recycled (3AM). It had appeared as if the recycle was what was killing us, as only the App Domain is recycled and not the complete worker process.

Immediately we had the guys here remove the nightly recycle and change it to a full IISReset. At least that way we had a workaround until we could determine the actual root cause, come up with a fix, and test said fix. However, it didn’t take long to determine the actual root cause…

One of the interesting things about this issue, was after it started happening in Production, a few of the other environments started exhibiting similar symptoms: Prod-Like and a smaller, sandbox environment. Mind you, neither of these environments had these issues during testing.

So, I took some time to dive in and actually figure out the problem. At first I thought it was because there were some metabase misconfigurations in these environments. I wouldn’t say that all of these environments were pristine, nor consistent between each other. I found a few things, but nothing really stood out…until…

While I was doing diffs against the various applicationHost.config files, NotePad++ told me it had been edited and needed to be refreshed (them removing the appPool recycles). However, as soon as this happened the 500 errors started. It didn’t help they did both machines at the same time which took down the whole application, but that’s another story.

This led me to believe that it wasn’t something within the configuration, but it also showed me how to reproduce it, at least part way. The part that I was missing was that I had to first hit the website to invoke the services and then change the configs causing an app domain recycle.

Then I attempted to connect to the worker process with windbg to see what it was doing. However, that was a complete failure as nothing actually happened to the process. No exceptions being thrown, no threads stuck, etc. It appeared to just sit there.

A bit of searching later led me to an article that had the exact same issues we were having, and that changing from a Classic to Integrated appPool fixed it. However, it didn’t mention why. Of course I tried it and it worked. To appease the customer’s inquiries I knew I needed to find out why though.

I still don’t have a great solution, but apparently net.tcp and WAS activation has to be done in Integrated mode. If it isn’t, you get the 500 error. But ours works fine until the app domain is recycled. Well, according to SantoshOnline, “if you are using netTcpBinding along with wsHttpBinding on IIS7 with application pool running in Classic Mode, you may notice the ‘Server Application Unavailable’ errors. This happens if the first request to the application pool is served for a request coming over netTcpBinding. However if the first request for the application pool comes for an http resource served by .net framework, you will not notice this issue.”

That would’ve been nice to know from Microsoft’s article on it, or at least a few more details. I remember reading an article about the differences between Integrated and Classic, but I sure don’t remember anything specific to this.

Anyways, hope this helps someone who runs into the same issue…

Windows 2008 Performance Alerts

This may seem silly to some of you, but I am still getting used to Windows 2008. Sadly, I don’t spend as much time actually administering servers as I used to (silly management), so it usually takes me a bit longer to make my way around 2008 than 2003. I like to think they made everything more complex, but for some reason I’m sure I’ll get booed about that.

Anyways, this morning I was attempting to setup some performance alerts on some servers we’re having issues with. Basically I wanted to have it email us when it reached a certain threshold. No big deal, thinking I had this, I created the email app, created a performance counter, and then manually added it in.

Needless to say that didn’t work. It took me awhile to figure out why too as my little email utility worked fine. So I began a new search in order to find out how stupid I was being.

Turns out, quite a lot of stupid. Instead of using the utility, you can now use scheduled task items…which includes an email action! I basically used the instructions over at Sam Martin’s blog, which, I may add, he posted about in April of this year. I’m not the only n00b. Plus, who doesn’t have an enterprise system that deals with this sort of stuff already (at least at the types of clients I work with)?

Perfmon

Open up perfmon
Create a new User Defined Data Collector Set
Choose to create manually after naming
Select Performance Counter Alert
Add in the performance counter you care about (mine was requests executing in asp.net apps 4.0)
Choose the user to run it as
Edit the Data Collector in the Data collector set
Change the sample interval to whatever works for you (I set mine to 60s so we can be on top of issues prior to the users)
Under Alert task, give it a name (e.g. EmailAlert) and give it a task argument (you can combine them to form a sentence like “the value at {date} was {value}”
Start the Data Collector Set

Schedule Tasks

Open up scheduled tasks
Create a task, not a basic task
Name it the exact same name you did in step 9 above (i.e. EmailAlert)
Check “user is logged in or not” so that it runs all the time
Create a new email action under the Action tab
Enter all the info for from, to, subject, etc. To send to multiple people, comma separate the addresses.
For the body, type whatever you want, and then $(Arg0) will pass the task argument you made in step 9 above.
Enter the SMTP server.

Done!

Since the performance counter was set to an application pool, whenever that pool disappears (IISReset, idle timeout, etc.) the counter stops.

Currently Reading (could take awhile): [amazon_image id=”B000QCS8TW” link=”true” target=”_blank” size=”medium” ]A Game of Thrones: A Song of Ice and Fire: Book One[/amazon_image]

Dummy Files

We are doing some document uploading to SharePoint, and needed some test files of various sizes. If you have Visual Studio installed, you have the tools required to make these files. Just make sure you run as administrator, and use the following command.

FSUTIL FILE CREATENEW 100MBTest.mdb 104857600

Usage: FSUTIL FILE CREATENEW [Filename] [Size in bytes]

Migration to WordPress Network

Well, the migration to a WordPress Network is nearing completion. All sites, except for my largest (in terms of uploaded content) have been migrated, and figuring out what I’m going to do with my Director install. This will save me so much time with upgrades and various other maintenance from now on.

I know that I had a post about this earlier, specifically how to do this on Dreamhost, but I thought I’d provide a few additional insights.

If you are using subdomains instead of folders, do not have Dreamhost tack on www to the root Network domain until after you’ve migrated all sites over. If you aren’t migrating, but simply setting up all new sites, then you don’t have to worry about it. This causes issues because it tries to resolve subdomain.domain.com to www.subdomain.domain.com, which doesn’t exist.
I am using full domains to map to the subdomains via the WordPress MU Domain Mapping plugin. If you want to have non-www resolve to www, make sure www.notnetworkdomain.com is your primary and notnetworkdomain.com is also listed.
If you have the Domain Mapping already setup to point to your www.notnetworkdomain.com during the migration, when you try to hit subdomain.networkdomain.com, it will redirect you to www.notnetworkdomain.com. That is, reverse mappings happen also, which is cool.
Depending on when you setup your domains at Dreamhost, it is possible their A records point to different IP addresses. Mirroring only works when they have the same A record IP. This happened to me on quite a few domains. To fix, simply delete the domain from Dreamhost, then recreate it as a mirror. Once the mirror is created, re-setup your custom MX records or any other DNS records you originally had.
Don’t import entries on a crappy network connection. It doesn’t work and continuously times out.

Outside of those issues, it went fairly painlessly. It also helps if you have someplace that has quickly updating DNS. I can’t tell you how many times I saw the “bad_http_conf” error, while I was waiting for DNS to propagate.

I’m also amazed at how easily most of the plugins have worked with the network config. I was really expecting more pains in that area.

Upgrade K2 Workflow Instances to a Specific Workflow Version

We were having a specific issue in our Dev and QA environments where K2 was consuming over 16GB of disk space, and subsequently causing our server to run out of disk space. We had an interim workaround of restarting the K2 service, but within a day of testing, it was possible that K2 would eat it all up again.

This was happening because workflow instances (cases in our example) are tied to specific versions of the workflow. Similar to .NET websites, in order for you to use a specific version it has to do a lot of pre-compiling. Now, I’m not sure why it was using so much disk space per version, but that is essentially what was causing all our issues.

There are a few things that could’ve made this better:

Testers and Developers not using old cases which are tied to older versions
Building our K2 workflows in Release instead of Debug

Turns out option #2 reduces the space an individual version uses by orders of magnitude. Sadly, there is no way to retrofit the processes that are actually already in K2.

The actual solution is to use some of the new APIs, specifically the Live Instance Management APIs (oh and that took awhile to find via searching). The downside is that these APIs were added in 4.5, so anyone on a version prior to that is screwed. Thankfully we were on 4.5.1!

Anyways, if you’re lazy, there is actually an already created utility on K2 Underground, and you can find out some additional info about it too.

Just be prepared for it not to work all that great. We received a ton of Null Reference errors while running the utility against our large database. It seemed to work fine in our POC, but not against the real thing. Some cases were changed, but not all, and we still had the same issue.

In the end, we had to manually go and delete the old cases in K2, which is definitely not supported. However, our app handles it gracefully, so it wasn’t a huge deal.

Clean-Up Winxs Folder

The folder gets large, but that is because of all the patches that are applied to your installation. Do not simply delete the files, because it could cause all sorts of havoc. The only way to actually reduce the size somewhat, is to have Windows remove any previous updates after you install a service pack. You can do this with the following command. I was able to clean up 4GB using the command. Nothing major, but amost 25% improvement.

dism /online /cleanup-image /spsuperseded

Run as administrator.

WordPress Network on Dreamhost

I’m just copying these instructions here, since I can’t seem to reliably access the website they are currently hosted on.

I think I’m going to change a few ways things are hosted here on my collection of sites. It is a pain to keep them all updated and managed. Therefore, I am looking into migrating to a WordPress Network (Multi-Site) setup. However, using subdomains doesn’t work with Dreamhost because of Dreamhost not allowing wildcards.

Here is the work-around (verbatim) from a fellow Dreamhost user.

Follow the directions for setting up your WordPress multisite (I will assume that you already know or have found the directions to do so).
Pick the subdomain feature while in setup.
Ignore the message you get saying that things may not work properly because of the Wildcard missing.
When you’ve followed all those wonderful instructions, create a test blog. You may end up with a URL like domain.comdatabase_name. I did, and continue to do so. Just edit that blog’s settings (Super Admin -> Sites -> Edit) so that the Path field only has a / in it. I’m unsure if this is a problem that user’s at other hosts have, or if it is exclusive and will soon be fixed, but once it is changed all is well.
Go to your Dreamhost Web Panel and mirror a subdomain for the blog you just added to the domain you set the multisite up on. NOTE: If you create blog.domain.comin WordPress multisite, you must create the same subdomain in your Web Panel — blog.domain.com. Visit blog.domain.com and verify that it leads you to the new blog you created.
If that works, then you need to install the Domain Mapping plugin for multisite.
This gives you a new menu to add a domain to your network and “park” it over a subdomain.
All you have to do is follow the directions there to add the domain, and you are set.
Just mirror that same domain to the multisite domain in your Dreamhost Web Panel, and everything should be in working order.

Now on to testing!

Self Signed SSL Certs

I’ve always hated creating self-signed SSL certs. It never seemed like there was a good and easy way to accomplish this. Yes, you could download the II6 Resource Kit, but that’s just one more thing I don’t need on my machine.

Well, in IIS7, there is actually an option to automatically create one. Technet has a good walkthrough of it. However, there are some limitations:

The common name is always the machine name of your IIS server.
The certificate is only valid for one week.
The certificate is not added to the “Trusted Root Certificate Authorities” of any browser.

Thankfully a remake of SelfSSL was created for IIS7 and it is more powerful, and easier to use. Take a look at Thomas Deml’s post on it to see the syntax and download the program. I’ve also uploaded it here, just in case anything happens to that site.

SelfSSL7